JP2003528461A - Method and system for achieving continuous motion sequential lateral solidification - Google Patents

Abstract

(57) Abstract: A method and system for processing an amorphous silicon thin film sample to produce a silicon thin film with controlled grain boundaries. The membrane sample includes a first edge and a second edge. In particular, using this method and system, a pulsed laser beam is generated using an excimer laser, and the pulsed laser beam is patterned such that each beamlet has sufficient intensity to melt the film sample. Masked to produce a focused beamlet. The film sample is continuously scanned by the patterned beamlet at a first constant predetermined speed along a first path between the first edge and the second edge. Also, the film sample is continuously scanned by the patterned beamlet at a second constant predetermined speed along a second path between the first edge and the second edge. You.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to methods and systems for processing thin film semiconductor materials, and in particular to large particles from amorphous or polycrystalline thin films on a substrate using laser irradiation and continuous motion of a substrate having a semiconductor film to be irradiated. And forming a semiconductor thin film having a controlled grain boundary position.

[0002]

[Prior art]

Several attempts have been made in the semiconductor processing field to convert amorphous silicon thin films into polycrystalline films using lasers. For example, James Im et al., “Crystall
ine Si Films for Integrated Active-Matrix Liquid-Crystal Displays "11 MR
S Bulletin 39 (1996) provides an overview of conventional excimer laser annealing techniques. In such conventional systems, the excimer laser beam is formed as a long beam, typically with a maximum length of 30 cm and a width of 500 μm or more. The beam thus formed is moved over a sample of amorphous silicon, promoting the melting of the amorphous silicon and the formation of polycrystalline silicon with controlled grain boundaries as the sample resolidifies.

The production of polycrystalline silicon using conventional excimer laser annealing techniques is problematic for several reasons. First, the polycrystalline silicon produced by this process is usually composed of small grains, has a random microstructure (ie, grain boundaries are not well controlled), and has a non-uniform grain size. However, this results in an inadequate and non-uniform device and thus a low yield. Second, in order to obtain grain boundary controlled polycrystalline thin films of acceptable quality, the yield of such thin films must be maintained at low levels. Also, this process generally requires a controlled atmosphere and requires the amorphous silicon sample to be preheated, which reduces production. So in this area,
There is a need to produce higher quality polycrystalline silicon thin films while maintaining higher yields. Similarly, manufacturing techniques are needed to produce polycrystalline silicon thin films with larger and more uniform microstructures that should be used in manufacturing higher quality devices such as thin film transistor arrays for liquid crystal panel displays. is there.

[0004]

[Problems to be Solved by the Invention]

It is an object of the present invention to provide a technique for producing a polycrystalline thin film semiconductor composed of large particles and having controlled grain boundary positions using a sequential lateral solidification process, and to produce such a silicon thin film at high speed. It is to be.

[0005]

[Means for Solving the Problems]

At least some of these objectives of the present invention are achieved using a method and system for converting an amorphous thin film sample or a polycrystalline thin film sample into a grain boundary controlled polycrystalline thin film or a single crystalline thin film. The membrane sample includes a first edge and a second edge. In particular, using this method and system, the laser beam generator is controlled to emit a laser beam, and a portion of this laser beam is of sufficient intensity for each beamlet to melt the film sample. Masked to produce a patterned beamlet having. The film sample is continuously scanned by the patterned beamlet along a first path between the first edge and the second edge at a first constant, predetermined velocity. Also, the film sample is continuously scanned by the patterned beamlet along the second path between the first edge and the second edge at a second constant predetermined velocity. It

In another embodiment of the invention, the film sample is first directed such that the fixed patterned beamlet continuously illuminates a first continuous portion of the film sample along a first path. Is continuously translated in the direction of. The first part melts during irradiation.
Also, the film sample is continuously translated in the second direction such that the fixed patterned beamlet illuminates a second continuous portion of the film sample along a second path. . The second part melts during irradiation. Further, after the membrane sample is translated in the first direction and the next successive portion of the first path of the membrane sample is illuminated, the first portion is cooled and resolidified and the membrane sample is In the direction of, and the next successive portion of the second path of the membrane sample is illuminated, the second portion cools and resolidifies.

In another embodiment of the invention, the film sample is positioned such that a given beamlet is incident on the film sample at a first position outside its boundary. Also,
The membrane sample can be finely translated from the first position to the second position before being scanned along the second path from the second position.

In another embodiment of the invention, the film sample is scanned along a second path and then irradiated by a beamlet at a third position outside the finely translated boundary of the film sample. Be translated as if to do. The film sample can then be moved so that the incidence of the beamlets moves from the third position to a fourth position outside the boundaries of the film sample. The film sample is then maintained with the patterned beamlets impinging on the fourth position after the movement is complete and until the vibration is complete.

In another embodiment of the invention, the film sample is continuously scanned in a first direction such that the fixed position beamlets scan a first path, and then the fixed position beamlets are scanned in a second direction. Are continuously scanned in the second direction so as to scan the path of. The film sample is translated in the first direction, and then the first direction is such that the patterned beamlets illuminate the first continuous portion of the film sample along the second path. It is continuously translated in a second opposite direction at a first constant predetermined velocity. The film sample is then finely translated so that the incidence of the beamlets moves from the first position to a second position outside the boundaries of the film sample. The film sample is then urged to illuminate the second continuous portion of the film sample along a second path until the patterned beamlet impinges on the second location.
Is continuously translated in a first direction opposite to the direction of at a second constant predetermined velocity.

[0010]

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a technique for producing crystalline thin film semiconductors composed of uniformly large grains and having controlled grain boundary positions using a sequential lateral solidification process. To fully understand this technique, one must first understand the sequential lateral solidification process.

The sequential lateral coagulation process consists of the sequential pulses emitted by the excimer laser:
A technique for producing a silicon structure composed of large particles by gradually translating a sample having a silicon film in one direction. As each pulse is absorbed by the silicon film, a small region of the film completely melts and resolidifies laterally, resulting in a crystalline region produced by the pulse prior to the pulse set.

An advantageous sequential lateral solidification process and apparatus for performing this process were filed on September 3, 1999 and assigned to a common assignee, the entire disclosure of which is incorporated herein by reference. And pending patent application 09/390537 (09/390537 application). Although this disclosure is made with reference to the particular techniques described in the 09/390537 application, it should be understood that other sequential lateral coagulation techniques can be readily configured for use with the present invention. .

FIG. 1a shows a system according to the present invention capable of implementing a continuous motion SLS process. As described in 09/390537, this system
An excimer laser 10, an energy density modulator 120 that rapidly changes the energy density of the laser beam 111, a beam attenuator / shutter 130 (optional in this system), and optics 140, 141, 142, and 143. And the beam homogenizer
144, lens beam steering systems 145, 148, masking system 150, and other lens beam steering systems 161, 162, 163,
Incident laser pulse 164, silicon thin film sample on substrate 170, sample translation stage 180, granite block 190, and support system 191,192,193,194,195
, 196, and a computer 100 that manages X and Y translations and microtranslations of the silicon film sample and substrate 170. Computer 100 directs such translation and / or fine translation by movement of the mask within masking system 150 or movement of sample translation stage 180.

Generating multiple excimer laser pulses of a given fluence, controllably modulating the fluence of the excimer laser pulses, and modulating as described in detail in the 09/390537 application A laser pulse is homogenized in a given plane, a portion of the homogenized modulated laser pulse is masked to produce a patterned beamlet, and the patterned beamlet is made into an amorphous silicon thin film sample. Irradiate, melting the part of the sample irradiated by the beamlets,
Controllable translation of the sample relative to the patterned beamlet and controlled modulation, thereby sequentially translating the sample relative to the patterned beamlet and patterning the variable fluence relative to the sample at corresponding sequential positions. The amorphous silicon thin film sample is converted into a single crystalline thin film or a polycrystalline thin film by converting the amorphous silicon thin film sample into a single crystalline silicon thin film or a polycrystalline silicon thin film in which grain boundaries are controlled by irradiation of the irradiated beamlets. It The following embodiments of the present invention will now be described with reference to the processing techniques described above.

FIG. 1b shows an embodiment of the process according to the invention for realizing a continuous motion SLS that can be used by the system described above. Specifically, the computer 100 may move the sample translation stage 180 (in the plane XY directions) and / or masking.
Control movement of system 150. Thus, the computer 100 controls the relative position of the sample 170 with respect to the pulsed laser beam 149 and the final pulsed laser beam 164. The frequency and energy density of the final pulsed laser beam 164 is also controlled by the computer 100 computer.

[0016] Pending patent application Ser. No. 09/390535 (No. 09/3905), filed September 3, 1999, also assigned to a common assignee, the entire disclosure of which is incorporated herein by reference.
No. 35 application), sample 170 can be translated with respect to laser beam 149 by moving masking system 150 or sample translation stage 180 to grow crystalline regions in sample 170. it can.
For example, for the purposes described above, the laser beam 149 has a length and width of 2 cm in the X direction,
It may be 1/2 cm in the Y direction (eg, rectangular), but pulsed laser beam 149 is not limited to such shape and size. In fact, of course, other shapes and / or sizes of the laser beam 149 known to those skilled in the art can be realized (eg square, triangular, etc.).

The final pulse from the transmitted pulsed laser beam 149, using various masks,
Laser beams and beamlets 164 can also be generated. Some examples of masks are shown in Figures 2a, 3a, 4a, and 6a, a detailed description of which has already been given in the 09/390535 application. For example, Figure 2a shows a mask 210 incorporating a regular pattern of slots 220, Figure 3a incorporates a pattern of chevrons 320, and Figure 6a depicts a mask 310 incorporating a pattern of diagonal lines 620. There is. For ease of explanation, below, each slit can be extended across the mask 410 by a homogenized laser beam 149 incident on the mask 410, resulting in nucleation within the illuminated area of the sample 170. A process according to the invention using a mask 410 (shown in FIG. 4a) incorporating a pattern of slits 420 which should have a width 440 narrow enough to prevent As discussed in the 09/390535 application, the width 440 depends on several factors, such as the energy density of the incident laser pulse, the duration of the incident laser pulse, the thickness of the silicon thin film, the temperature of the silicon substrate and the Depends on thermal conductivity.

In the exemplary embodiment shown in FIG. 1b, sample 170 is 40 cm in size in the Y direction and 30 cm in the X direction. The sample 170 is conceptually subdivided into a number of columns (eg, first column 5, second column 6, etc.), and the position / dimensions of each column are stored in a computer 100 storage device. Used by name. Each row is, for example, 2 cm in the X direction and 40 cm in the Y direction.
Is. Thus, the sample 170 can be conceptually subdivided into, for example, 15 columns. Sample 170 with different dimensions (eg 3cm x 40cm)
It is also possible to subdivide it into several columns with sample
When conceptually subdividing 170 into several rows, it eliminates the possibility that at least a small portion of one row that extends the length of such a row will overlap some of the neighboring rows, leaving unexposed areas. Should be. For example, the width of the overlapping area may be, for example, 1 μm.

After conceptually subdividing the sample 170, a pulsed laser beam 111 was activated (either by using the computer 100 to activate an excimer laser or by opening the shutter 130) and (pulse). From laser beam 149) first position 2
Generate a pulsed laser beamlet 164 that is incident on 0. Then sample 17
The zero is translated and accelerated in the forward Y direction under the control of computer 100 to reach a predetermined velocity for the fixed position beamlets in the first beam path 25.

[Equation 1] Vmax = Bw ・ f

(In Equation 1 above, Vmax is the maximum movable velocity of the sample 170 with respect to the pulsed beamlet 164, and Bw is the width of the pattern of the pulsed laser beamlet 164 (or of the pulsed beamlet 164). Is the width of the envelope) and f is the frequency of the pulsed beamlet 164), and the predetermined velocity V
The pred can be determined.

[Equation 2] Vpred = Vmax − K

In the above equation 2, K is a constant and is used to eliminate the possibility that there is a non-irradiated region between the irradiation regions adjacent to each other. Since the sample 170 is continuously translated, it is not necessary to block or turn off the pulsed beamlet 164, so that the system according to the invention shown in FIG. It is also possible to use.

The pulsed beamlet 164 reaches the upper edge 10 ′ of the sample 170 when the moving speed of the sample 170 with respect to the pulsed laser beam 149 reaches a predetermined speed Vpred. The sample 170 is continuously (ie, without stopping) in the forward Y direction at a predetermined velocity Vpred so that the pulsed beamlet 164 continues to illuminate successive portions of the sample over the entire length of the second beam path 30. ) Can be translated. Pulse beamlet
When the 164 reaches the lower edge 10 "of the sample 170, the translation of the sample 170 moves to the second position.
The pulse beamlets 164 (in the third beam path 35) are decelerated to reach 40. After the pulsed beamlets 164 continuously and sequentially irradiate successive portions of the sample 170 along the second beam path 30, these successive portions of the sample 170 are completely melted. Pulse beamlet 164 is at the bottom edge of sample 170
After passing through 10 ″, a crystallized silicon thin film region 540 (eg, grain boundary controlled polycrystalline silicon thin film) is formed in the irradiated second beam path 30 region of the sample 170. Note that a portion of the crystallized silicon thin film region 540 is shown in Figure 5b This grain boundary controlled polycrystalline silicon thin film region 540
Extend over the entire length of the second irradiation beam path 30. Pulse beamlet 16
Note that 4 does not need to block the pulsed laser beam 149 as it no longer illuminates the sample 170 after traversing the lower edge 10 ″ of the sample 170.

Thereafter, in order to eliminate the large number of small initial crystals 541 formed at the melting boundary 530,
Sample 1 while the position of pulse beamlet 164 along the Y direction is fixed
70 is finely translated along the fourth beam path 45 in the X direction over a predetermined distance to reach the third position (eg, 3 micrometers), and then along the fourth beam path 50. Under the control of the computer 100 to reach a predetermined translational velocity for the pulsed beamlet 164 (in the upper edge of the sample 170).
Acceleration to 10 '). Pulse beamlet 164 is sample 1 for it
The bottom edge 10 ″ of the sample 170 is reached when the velocity of 70 reaches a predetermined velocity Vpred. The sample 170 causes the pulsed beamlet 164 to illuminate the sample 170 over the entire length of the fifth beam path 55. Is continuously (ie, without stopping) translated in the reverse Y direction at a predetermined velocity Vpred.
Is translated under the control of the computer 100 so as to reach the upper edge 10 ′ of the sample 170, the translation of the sample 170 reaches the fifth position 65 (in the sixth beam path 60). Again) for pulsed beamlets 164. When the fifth beam path 55 is so illuminated, the regions 551, 552, 553 (shown in FIG. 5b) of the sample 170 cause the remaining amorphous silicon thin film 542 and the polycrystalline silicon thin film region 540 to initially grow. The crystallized region 543 melts, while the central portion 545 of the polycrystalline silicon thin film remains solidified. After the pulsed beamlets 164 continuously and sequentially illuminate successive portions of the sample 170 along the fifth beam path 55, these consecutive portions of the sample 170 are completely melted. Therefore, the laser beam 149 continuously illuminates the fifth row 5 over the entire length of the fifth beam path 55 (that is, without stopping), so that continuous illumination along the second beam path 30 occurs. As the melted regions 542, 542 of the thin film formed as a result of this solidify, a crystal structure forming the central portion 545 grows on the outside. Therefore, a polycrystalline silicon thin film composed of long grains whose direction is controlled is formed on the sample 170 along the entire length of the fifth beam path 55. A portion of such a crystallized structure is shown in Figure 5c. Therefore, using the continuous motion SLS procedure described above, it is possible to continuously form the crystallized structure of the figure along the entire length of the row of samples 170.

The sample 170 is then moved to the next row 6 via the seventh beam path 70 to reach the fifth position 72, and when moved to the fifth position 72, the sample 170 is moved.
The vibration can be stopped at this position so that it can be stopped. In fact, if the sample 170 reaches the sixth column 6, then the sample 170 is (X
It is moved about 2 cm for a row that is 2 cm wide. The procedure described above for the irradiation of the first row 5 can then be repeated for the second row 6. In this way, all rows of sample 170 can be properly illuminated with only the shortest rest time needed to bring sample 170 to rest (and thus wait for sample 170 to stop vibrating). In fact, the time required to quiesce the sample 170 is the time the laser has completed illuminating the entire row of samples 170 (eg, the fifth row 5) and the time that the sample 170 has passed the next row (eg, the second row 5). Only the time to move to column 6).
Using the exemplary dimensions of sample 170 above (30 cm x 40 cm), the dimensions of each row are 2 cm x 40 cm, so there are 15 rows that must be illuminated for this exemplary sample 170. Not too much. Therefore, the number of “moving and stationary” delays that can occur in the exemplary sample 170 is 14 or 15.

To show the time savings when using the continuous motion SLS procedure according to the invention for producing crystallized silicon thin films, the length of various travel paths of sample 170 (sample size, row size, and The time required to translate the sample 170 (having laser beam dimensions) can be estimated as follows. First beam path 25 0.1 s Second beam path 30 0.5 s (Because sample 170 does not need to stop and stop over the entire length of the column and translate continuously) Third beam path 35 0.1 s Fourth Beam path of 45 0.1 seconds Fifth beam path 50 0.1 seconds Sixth beam path 55 0.6 seconds (again because sample 170 translates continuously without needing to stop and rest over the entire length of the row) Seventh beam path 60 0.1 seconds Eighth beam path 70 0.1 seconds Thus, the total time to completely illuminate each row 5, 6 of sample 170 is 1.6.
Seconds (or at the longest, for example 2 seconds). Thus, for 15 rows of sample 170, the total time to form a grain boundary controlled polycrystalline silicon thin film (for the entire sample 170) is about 40 seconds.

As pointed out above, it is also possible to use different sizes and / or shapes for the cross section of the laser beam 149. For example, a pulsed laser beam 149 with a cross-sectional area of 1 cm x 1 cm (ie square) can be used. It should be appreciated that it is advantageous to use the diameter of the pulsed beamlets 164 as one of the dimensional parameters for each row. In this example, (1 cm pulse beamlet 164
30 cm x 40 cm sample 170 is conceptually subdivided into 30 rows with a dimension in the X direction of 1 cm and a dimension in the Y direction of 40 cm (assuming a cross-section of the diameter of the pattern). You can The use of such a pattern of pulsed beamlets 164 increases the predetermined translational velocity Vpred of sample 170 and, in some cases, pulsed beams.
It is possible to reduce the total energy of the laser beam 149. Thus, the systems and methods according to the present invention illuminate the sample through 30 rows rather than illuminating the sample through 15 rows. Despite the longer time it takes to move from row to row and stand still for 30 rows (compared to 15 rows above),
Due to the smaller column width, focusing the laser pulse energy on a smaller beamlet pattern allows the pulsed laser beam 149 to have a higher intensity and effectively crystallize the sample 170, And since the total irradiation completion time of the sample 170 is not so long as compared with the sample having 15 rows, the sample translation speed is high.

According to the invention, the mask described and shown in the 09/390535 application can be used in the continuous motion SLS procedure shown in FIG. 1b. For example, using mask 310 with masking system 150, the processed sample (ie, crystallization region 3
The portion 350) shown in FIG. 3b, having 60, is produced. Each crystalline region 360 consists of a diamond-shaped single crystalline region 370 and two grain-bounded polycrystalline silicon regions 380 in the tail of each chevron that are composed of long grains and are oriented. A mask 610 (shown in Figure 6a) that incorporates a pattern of diagonal slits 620 can also be used.
In the case of this mask 610, the sample 170 is continuously translated in the Y direction and the mask 610 is used in the masking system 150 of FIG.
The portion 650) shown in FIG. 6b, having 660, is produced. Each crystallized region 660 consists of a crystalline region composed of long grains with grain boundaries 670 with controlled orientation.

It is also possible to illuminate the sample 170 along each row that is not parallel to the edges of the square sample 170. For example, each row can extend approximately 45 degrees with respect to the edge of sample 170. The computer 100 stores the start and end points of each column, and along the columns parallel to each other inclined with respect to the edge of the sample 170 by, for example, 45 degrees.
The procedure shown in b can be performed. Sample 170 along parallel rows that are tilted at other angles (eg, 60 degrees, 30 degrees, etc.) to the edge of sample 170
It can also be irradiated.

In another exemplary embodiment of the method according to the invention shown in FIG. 7, the sample 170 is conceptually subdivided into several columns. After subdividing sample 170 (see Figure 1b
Pulsed beamlet first incident on the first position 20 (as in the embodiment shown in FIG.
The pulsed laser beam 140 can be turned on (by using the computer 100 to activate the excimer laser or opening the shutter 130) so that 164. The sample 170 is then added to the first beam path 70.
Under the control of computer 100, it is translated and accelerated in the Y direction to reach a predetermined sample translation velocity Vpred for pulse beamlet 164 in zero. The pulsed beamlet 164 (and the beamlet) reaches the upper edge 10 ′ of the sample 170 when the moving velocity of the sample 170 with respect to the pulsed laser beam 149 reaches a predetermined velocity Vpred. The sample 170 is then placed at a predetermined velocity Vpre so that the pulsed beamlet 164 illuminates the sample 170 over the entire length of the second beam path 705.
Translated continuously (ie, without stopping) and sequentially in the Y direction at d. When the pulsed beamlet 164 reaches the lower edge 10 ″ of the sample 170, the translation of the sample 170 is relative to the pulsed beamlet 164 (in the third beam path 710) so as to reach the second position 715. After the pulsed beamlets 164 have passed the lower edge 10 "of the sample 170, the entire sample 170 along the second beam path 705 has completely melted and then solidified.

The sample 170 is translated toward the upper edge 10 ′ of the sample 170 in the reverse Y direction without any slight translation in the X direction. Specifically, sample 170 has its lower edge 10 "
To reach a predetermined sample translation velocity Vpred before reaching
Acceleration in the negative Y direction along the fourth beam path 720 under control of Then
The sample 170 has a predetermined velocity Vpred so that the pulsed beamlets 164 continuously and sequentially illuminate the sample 170 along the entire length of the fifth beam path 725 (along the path of the second beam path 705). Continuously in the negative Y direction (ie without stopping)
Can be translated. When the pulsed beamlet 164 reaches the lower edge 10 ″ of the sample 170, translation of the sample 170 (in the sixth beam path 730) occurs until the beamlet 164 strikes the first position 20. The second beam path after the pulsed beamlet 164 passes through the lower edge 10 "of the sample 170.
The entire sample 170 illuminated along 705 melts completely and then solidifies. Thus, upon completion of this pass, the surface of sample 170 corresponding to fifth beam path 725 will partially melt and resolidify. In this way, the resulting film surface can be further smoothed. Also, using this technique, a pulsed laser beam
The energy output of 149 and (pulse beamlet 164) can be reduced to effectively smooth the surface of the film. Similar to the technique of FIG. 1b, a grain boundary controlled polycrystalline silicon thin film region 540 is formed in the illuminated region of the sample 170.
A portion of the polycrystalline silicon thin film region 540 is shown in Figure 5b. This grain boundary controlled polycrystalline silicon thin film region 540 has second and fifth irradiation beam paths 702, 70.
It extends over the entire length of 5. Again, the pulsed beamlet 164 is the sample
After traversing the lower edge 10 "of 170 and no longer illuminating sample 170, a pulse
Note that it is not necessary to block the laser beam 149.

The sample 170 is then finely translated (eg, 3 micrometers) in the X direction along the seventh beam path 735 for a predetermined distance until the pulsed beamlet strikes the third position 740. , Then in the forward Y direction (toward the lower edge 10 ″ of sample 170) under the control of computer 100 to reach a predetermined translational velocity for pulsed beamlet 164 along eighth beam path 745. The pulsed beamlet 164 is accelerated such that the translational velocity of the sample 170 with respect to it is a predetermined velocity Vpred.
When reaching the upper edge 10 ′ of the sample 170. Sample 170 is then
The pulsed beamlets 164 are translated continuously (ie, without stopping) in the forward Y direction at a predetermined velocity Vpred so as to continuously and sequentially illuminate the sample 170 over the entire length of the ninth beam path 55. . When the pulsed beamlet 164 reaches the lower edge 10 ″ of the sample 170, translation of the sample 170 causes a pulse (in the tenth beam path 760) until the pulsed beamlet 164 strikes the fifth position 765.・ Beamlet
Slowed down for 164. The pulse beamlet 164 is shown at the bottom edge 10 of the sample 170.
Note that after traversing the ", the entire sample 170 illuminated along the ninth beam path 750 is completely melted and then resolidified.

Thereafter, the translation direction of the sample 170 is (beam paths 770, 775, 780) without fine translation.
Each of these paths of the sample 170 is reversed again (via) and continuously translated in the reverse Y direction (also extending along the ninth beam path 750) at a predetermined velocity Vpred. Irradiation is continuous and sequential. Thus, upon completion of this pass, the surface of sample 170 corresponding to beam path 775 will partially melt and resolidify. The surfaces of these paths 745-780 are smoothed by translation in the forward and reverse Y directions and irradiation of the sample 170 (without fine translation) along the same beam path. As a final product of such a procedure, a crystallized structure composed of large grains with controlled grain boundaries, having a flat (or even flatter) surface, is produced along the entire row of sample 170.

The sample 170 is then moved to the next column (ie, the second 6) until the beamlet is incident on the fifth position 790 via the other beam path 785, and the pulse
If vibration of the sample 170 and stage 180 occurs when the sample 170 is moved to a position where the beamlet 164 is incident on the fifth position 790, it can be stationary so as to damp it. This procedure is repeated for all columns of sample 170, similar to the procedure described above and shown in Figure 1b.

Referring now to FIG. 8, the steps performed by computer 100 computer to control the silicon thin film crystallization growth method performed by the procedure shown in FIGS. 1b and / or 7 are described below. To do. For example, various electronics of the system shown in FIG. 1 are initialized by computer 100 at step 1000 to begin the process. Then, in step 1005, the amorphous silicon thin film sample 170 on the substrate is placed on the sample translation stage 180. It should be noted that such placement of the sample on the stage can be performed manually or by a robot under the control of computer 100. Next, in step 1015, the sample translation stage 180 is moved to the initial position. Step 1015 can include alignment to a reference topography on sample 170. At step 1020, various optical elements of the system are adjusted and focused as needed. Then, in step 1025, the laser is driven to the desired energy level and pulse as needed to completely melt the amorphous silicon sample over the cross-sectional area of each pulsed beamlet impinging on the sample, according to the particular process to be performed. Stabilized at repetition rate. Step 1030
Then, the attenuation of pulse beamlet 164 is adjusted as needed.

Next, in step 1035, the shutter is opened (or the computer is activated to turn on the pulsed laser beam 149) and the pulse beamlet 164 is applied to the sample 170.
Can be irradiated, and thus the continuous motion sequential lateral coagulation shown in FIGS. 1b and 7 can be initiated. The sample is continuously translated in the Y direction, while simultaneously illuminating the first beam path of the sample (eg, sample along the second beam path 30) continuously and sequentially (step 1040). Sample 170 is Y at predetermined speed Vpred
Continuously translated in the direction, and at the same time, the sample (eg, the sixth beam path)
A second beam path of (sample along 55) is sequentially and continuously illuminated (step 1045). With regard to FIG.
Translate continuously along 0 and simultaneously illuminate sample 170 continuously and sequentially,
Then, the sample 170 is decelerated along the third beam path 35 to move the sample 170 to the fourth beam path 45.
A small translation along the X direction, waiting for the sample 170 to stand still, accelerating along the fifth beam path 50, and then continuously translating the sample 170 along the sixth beam path 55. At the same time, the sample 170 can be regarded as continuous and sequential irradiation. Thus, the entire row of samples 170 is sequentially illuminated. If some portion of the current row of sample 170 is not illuminated, computer 100 causes sample 170 to move at a predetermined rate in a particular direction such that other portions of the current row of sample 170 that have not been illuminated are illuminated. Control is performed so that Vpred continuously translates (step 1055).

Then, if crystallization of a region of sample 170 is complete, steps 1065, 106 are performed.
At 6 the sample is repositioned (ie moved to the next column or row, ie the second column 6) with respect to the pulsed beamlet 164 and the crystallization process is repeated on the new path. If no other path is specified for crystallization, step
The laser is shut off at 1070, the hardware is shut down at step 1075, and step 10
At 80 the process is complete. Of course, if additional sample processing is required, or if the invention is used for batch processing, step 1005 for each sample,
1010 and 1035 to 1065 can be repeated. One of ordinary skill in the art will appreciate that the sample can be continuously translated in the X direction and slightly translated in the Y direction. In practice, as long as the travel paths of the pulsed beamlets 164 are parallel to each other and continuous and extend from one edge of the sample 170 to the other edge of the sample 170, the sample 170 is continuously continuous in any direction. It is possible to translate.

The foregoing merely illustrates the principles of the invention. Various modifications and alterations to the above-described embodiments will be apparent to those skilled in the art in view of the teachings herein. For example, the amorphous silicon film sample or the polycrystalline silicon film sample 170 can be replaced with a sample having a predetermined island of such silicon film. Also, while the above exemplary embodiment describes a laser system in which the laser beam is fixed and preferably non-scannable, the method and system according to the invention can deflect at a constant velocity along the path of a fixed sample. It should be appreciated that pulsed laser light can be used. Thus, those skilled in the art will be able to envision numerous systems and methods that, while not explicitly shown or described herein, implement the principles of the present invention and are therefore within the spirit and scope of the invention. Will be understood.

[Brief description of drawings]

FIG. 1a is a diagram of an exemplary embodiment of a system for continuous motion coagulation lateral coagulation (“SLS”) in accordance with the present invention. FIG. 1b shows an embodiment of the method according to the invention for realizing continuous motion SLS usable by the system of FIG. 1a.

FIG. 2a is a diagram of a mask having a dotted pattern. 2b is a partial view of the crystallized silicon film resulting from the use of the mask shown in FIG. 2a in the system of FIG. 1a.

FIG. 3a is a diagram of a mask having a chevron pattern. 3b is a diagram of a portion of the crystallized silicon film resulting from using the mask shown in FIG. 3a in the system of FIG. 1a.

FIG. 4a is a diagram of a mask having a line pattern. FIG. 4b is a partial view of the crystallized silicon film resulting from using the mask shown in FIG. 4a in the system of FIG. 1a.

FIG. 5a is an exemplary diagram showing a portion of an illuminated area of a silicon sample using a mask having a line pattern. FIG. 5b shows an irradiation area of a silicon sample using a mask with a line pattern after the initial irradiation and translation of the sample and after application of a single laser pulse in the method shown in FIG. 1b. FIG. FIG. 5c is an exemplary view of a portion of the crystallized silicon film after the second irradiation that was produced using the method shown in FIG. 1b.

FIG. 6a is a diagram showing a mask having a diagonal pattern. FIG. 6b is a partial view of the crystallized silicon film resulting from using the mask shown in FIG. 6a in the system of FIG. 1a.

7 shows another embodiment of the method according to the invention for realizing continuous motion SLS usable by the system of FIG. 1a.

[Figure 8]   FIG. 3 is a flow diagram showing steps performed by the method shown in FIG. 1a.

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Claims (22)

[Claims] 1. A method of processing a silicon thin film sample having a first edge and a second edge to produce a crystalline silicon thin film, comprising: (a) emitting a laser beam from a laser beam generator. And (b) a portion of the laser beam so that each beamlet produces a patterned beamlet having sufficient intensity to impinge on and melt the film sample. And (c) so that the incidence of the patterned beamlet travels along a first path on the film sample between the first edge and the second edge, Continuously scanning a film sample with a patterned beamlet at a first constant, predetermined velocity; and (d) incidence of the patterned beamlet on a first edge and a second edge. Between the department As moving along a second path on a sample, the method comprising the steps of continuously scanning the film sample at a second constant predetermined speed by a patterned beamlet. 2. The step (c) comprises continuously translating the film sample such that the patterned beamlet sequentially illuminates a first continuous portion of the film sample along a first path, The first portion comprises melting during irradiation, and step (d) comprises irradiating the patterned beamlet to a second successive portion of the film sample sequentially along a second path, The method of claim 1, comprising continuously translating the film sample, the second portion melting during irradiation. 3. The membrane sample is translated along a first path and after irradiation of the next first successive portion of the membrane sample, the already irradiated first portion recoagulates, The membrane sample is translated along a second path, and after irradiation of the next second successive portion of the membrane sample, the already irradiated second portion re-solidifies. Item 2. The method according to Item 2. 4. The first path is parallel to the second path, in step (c) the membrane sample is continuously scanned in a first direction, and in step (d) the membrane sample is secondly scanned. 2. The method of claim 1, wherein the first direction is opposite to the second direction, with the first direction being continuously scanned. 5. The method of claim 1, wherein the first edge is located on the side of the membrane sample opposite the side on which the second edge is located. 6. (e) Positioning the film sample prior to step (d) such that the patterned beamlet is incident on the film sample at a first location outside the boundaries of the film sample. And (f) a film sample such that the incidence of the patterned beamlet moves from a first position to a second position between the end of step (e) and the start of step (d). The method of claim 2, further comprising: micro-translating, wherein step (d) is initiated when the patterned beamlet is incident on the second location. 7. (g) Positioning the film sample after step (d) such that the patterned beamlet is incident on a third position outside the boundary of the film sample; ), After step (g), moving the film sample such that the incidence of the patterned beamlet moves from the third position to a fourth position outside the boundary of the film sample; i) after step (h), maintaining the film sample such that the patterned beamlet is incident at the fourth position until the vibration of the film sample is dampened. The method according to claim 6, wherein 8. (j) After step (i), further repeating steps (c) and (d) for the respective third and fourth paths of the patterned beamlets on the film sample. The method of claim 7, comprising: 9. The membrane sample is continuously scanned in a first direction in step (c), the membrane sample is continuously scanned in a second direction in step (d), and (k) step ( After c), the film sample is continuously moved at a first constant, predetermined velocity such that the incidence of the patterned beamlet travels along a first path to reach a first position. And a patterned beamlet illuminates a first continuous portion of the film sample, the film sample being translated in a direction opposite to the first direction, and (l) step (l). Between the end of k) and the start of step (d), the film is moved so that the incidence of the patterned beamlet moves from a first position to a second position outside the boundary of the film sample. A step of finely translating the sample, and (m) After steps (l) and (d), the film sample is moved to a second constant position so that the incidence of the patterned beamlet moves along the first path to reach the second position. Continuously translating at a predetermined velocity of the patterned beamlet illuminates a second continuous portion of the film sample, the film sample being translated in a direction opposite to the second direction. The method of claim 2 including: 10. The film sample such that (n) after step (m), the incidence of the patterned beamlet moves from outside the boundary of the film sample to a second position to a third position. And (o) maintaining the film sample such that the patterned beamlet is incident at the third position until the vibration of the film sample is dampened. The method according to claim 9. 11. (p) Step (p)? , Step (c), (d), (k), (l), and so that the incidence of the patterned beamlet travels along respective third and fourth paths of the film sample. 11. The method of claim 10, further comprising the step of repeating (m). 12. A system for converting a polycrystalline silicon thin film sample having a first edge and a second edge into a crystalline thin film, comprising: a memory storing a computer program; and (a) a laser beam generator. Controlling each of the beamlets to emit a laser beam, (b) so that each beamlet produces a patterned beamlet having an intensity sufficient to impinge on and melt the film sample. Masking a portion of the laser beam at (c) the incidence of the patterned beamlet along a first path on the film sample between the first edge and the second edge. Continuously moving a film sample with a patterned beamlet at a first constant predetermined velocity to move; and (d) the patterned beamlet. The patterned beamlet causes the film sample to have a second constant predetermined dimension such that the incident travels along a second path on the film sample between the first edge and the second edge. A processor for executing a computer program to perform the steps of continuously scanning at a speed of. 13. The processor continuously translates and patterns the film sample such that the incidence of the patterned beamlet moves along a first path during performing step (c). The irradiated beamlets irradiate a continuous first portion of the film sample, the first portion melts during irradiation, and the processing device removes the patterned beamlets from the patterned beamlets while performing step (d). The film sample is continuously translated such that the incident travels along a second path, and the patterned beamlet illuminates a continuous second portion of the film sample,
13. The system of claim 12, wherein the portion of the melts during irradiation. 14. The processing device translates the film sample such that the patterned beamlet illuminates the next first continuous portion along the first path of the film sample before the first sample. The already irradiated first portion along the path is re-solidified and the processor irradiates the patterned beamlet to the next successive second portion along the second path of the film sample. 14. The system of claim 13, wherein after translating the membrane sample, the already irradiated second portion along the second path recoagulates. 15. The first path is parallel to the second path and the processor continuously scans the membrane sample in the first direction while performing step (c), the processor 13. The system of claim 12, wherein the film sample is continuously scanned in a second direction while performing step (d), the first direction being opposite to the second direction. 16. The system of claim 12, wherein the first edge is located on the side of the membrane sample opposite the side on which the second edge is located. 17. The processing apparatus comprises: (e) prior to step (d), the patterned beamlet is incident on the film sample at a first location outside the boundary of the film sample. Positioning the sample, and (f) the incidence of the patterned beamlet moving from the first position to the second position between the end of step (e) and the start of step (d). Performing each additional step of finely translating the film sample such that the processing device performs step (d) such that the patterned beamlet is initially incident at the second position. 14. The system of claim 13, wherein 18. The processing apparatus positions the membrane sample such that (g) after step (d) the patterned beamlet is incident on a third location outside the boundaries of the membrane sample. And (h) move the film sample such that the incidence of the patterned beamlet moves from the third position to a fourth position outside the boundary of the film sample after step (g). And (i) after step (h), each additional step of maintaining the film sample such that the patterned beamlet is incident at the fourth position until the vibration of the film sample is damped. 13. The system of claim 12, wherein the system executes 19. The processing apparatus comprises: (j) step (c) after step (i) for incidence of the patterned beamlets along respective third and fourth paths on the film sample. 19. The system of claim 18, performing the additional steps of repeating) and (d). 20. The processor continuously translates the membrane sample in a first direction during performing step (c), and the processor treats the membrane sample during performing step (d). Continuously translating in a second direction such that the processor follows (k) step (c) along a first path such that the incidence of the patterned beamlet reaches a first position. Moving the film sample continuously in translation at a first constant predetermined velocity, the patterned beamlet illuminating a first continuous portion of the film sample, the film sample Translation in the direction opposite to the direction of 1, and (l) the incidence of the patterned beamlet at the first position between the end of step (k) and the start of step (d). From the second position outside the boundary of the membrane sample A fine translation of the film sample so as to move to a first position such that (m) after steps (l) and (d) the incidence of the patterned beamlet reaches a second position. The film sample is continuously translated at a second constant predetermined velocity so as to travel along the path, and the patterned beamlets illuminate a second, contiguous portion of the film sample, 14. The system of claim 13, further comprising performing each additional step of being translated in a direction opposite to the second direction. 21. The processing apparatus comprises: (n) after step (m), the incidence of the patterned beamlet is moved from outside the boundary of the film sample to a second position to a third position. Moving the membrane sample, and (o) maintaining the membrane sample such that the patterned beamlet is incident at the third position until the vibration of the membrane sample is damped. 21. The system of claim 20, executing. 22. The processing device comprises: (p) after step (o), moving the incidence of the patterned beamlet along respective respective third and fourth paths of the film sample. c
22. The system of claim 21, performing additional steps of repeating), (d), (k), (l), and (m).